Blade connection means for power-operated slicing knife



Dec. 31, 1968 D. M. BAUER 3,418,713

BLADE CONNECTION MEANS FOR POWER-OPERATED. SLICING KNIFE Filed March 24, 1967 j Arty/7 y United States Patent 1 3,418,713 BLADE CONNECTION MEANS FOR POWER- OPERATED SLICING KNIFE Douglas M. Bauer, Danvers, Mass., assignor to General Electric Company, a corporation of New York Filed Mar. 24, 1967, Ser. No. 625,799 6 Claims. (Cl. 30-272) ABSTRACT OF THE DISCLOSURE The disclosure herein shows a power-operated slicing knife with an improved latching structure for removable attachment of the knife blades.

BACKGROUND OF THE INVENTION (1) Field of the invention.The invention herein pertains to a power operated slicing knife and, more particularly, to a novel latching mechanism for easy attachment and removal of the blades from the power unit.

(2) Description of the prior art.Numerous latching devices for electric slicing knife blades are well-known and many variations have been provided. Many of the latching devices are mechanically complex, or are subject to wear because of high friction; other arrangements lack needed safety features or present complex cleaning problems. The invention described herein is a specific im provernent upon that shown in US. Patent 3,153,852 of common assignment. In small appliances of the type noted, it is necessary to provide the parts as simply and cheaply as possible, as well as making them long-wearing, free from stresses, and with as few moving parts as possible. Latching mechanisms that extend out of the handle have the disadvantage of being exposed. Additionally, it is more dilficult to clean the blades when the latching mechanism is attached directly to the blade tangs as in the referenced patent. Furthermore, it is desirable to space the latching mechanism away from the switch or trigger to prevent any accidental actuation while the blades are being attached or detached. It is known to use pushbutton latches which employ complex high-wearing mechanisms that add to the cost of manufacture and maintenance.

SUMMARY OF THE INVENTION Briefly described, the present invention is directed to an electrically operated slicing knife which has a housing with an opening at one end preferably on the longitudinal centerline of the housing for the cutting blades. An electric motor is carried within the housing and is adapted to be connected to a source of power either by a cord or batteries as desired. A pair of driven members in the housing is connected to the motor and driven by the motor to provide a counter-reciprocating motion. A pair of knife blades each having a forward cutting portion and a rearward tang portion are adapted to be inserted into the housing opening and to be driven by the motor in a well-known manner. To this combination the invention improves on a latching mechanism which preferably comprises a lateral projection on each tang portion of the blade, which projection is directed outwardly or away from the centerline of the housing. A resilient latch member is connected to each driven member and is biased inwardly. The latch member is provided with an aperture means for driving engagement with the tang projection when the tang is inserted in the opening. A pair of separate supported overlapping counter-reciprocating actuators on opposite sides of the centerline are provided. Each actuator extends beyond the housing at one end and is connected to the remote resilient latch member on its other end whereby a pinching motion by the operator on one end of each actuator spreads the latches by operating on the opposite latching member to force the latches apart and separate the engagement to release the tangs from the housing. Additionally, the resilient latch member may be a longitudinal extending spring member that is cantilever-connected to the driven member with its free end biased inwardly. Further, a specific connection means between the latch and its remote actuator is provided to maintain the parts together while providing for line transverse operation of the latching mechanism. Thus, the main object of this invention is to provide an improved latching structure that is easy to manufacture, reliable in operation, completely enclosed to prevent damage to the latching mechanism, and provides for a safer and longer wearing appliance.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a power-operated slicing knife which incorporates this invention, a portion of the knife blades being deleted for clarity;

FIG. 2 is a partial perspective view of the rear portion of the knife blades removed from the handle hous- FIG. 3 is a partial perspective view of one driven member of the slicing knife which is adapted for connection to a knife blade;

FIG. 4 is a partial plan sectional view illustrating the latching mechanism; and

FIG. 5 is an exploded perspective view of the latching structure shown in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1 there isshown a power-operated slicing knife having a housing or handle 10 and a pair of knife blades 12 and 14. Housing 10 is provided with a blade receiving opening 16 at one end that may be generally symmetrical with the longitudinal centerline 18 of the housing. The housing enclose-s the driving mechanism of the knife including an electric motor 20, a transmission 22 and a pair of driven connecting members 24 and 26. Transmission 22 provides means for converting the rotary motion of motor 20 about an axis which may be parallel to the longitudinal axis 18 of the housing, to a reciprocating motion to drive blades 12 and 14 with counter-reciprocating motion in short rapid axial strokes.

As shown also in FIG. 2, the knife blades include forward cutting portions 28 and 30 and rearward tang portions 32 and 34 respectively. The structure thus far described is generally shown in said Patent 3,153,852 and is well-known for providing reciprocating motion to the blades of a slicing knife.

In order to provide an improved latching mechanism for a clean uncluttered blade for ease in handling and cleaning, it is desirable to maintain the tang portion of the blades as free of obstruction as possible. To this end, the tang portions which are adapted for insertion in the opening 16 in the housing, are offset straight sided portions 32 and 34 rearward of the deflector 36. The only structure on each of the tang portions consists of a lateral engagement member such as the projection 38 which may preferably be a cylindrical button secured in any manner into the outwardly facing side of the tang portion and oriented or directed toward the outside of the housing.

Since, in the symmetrical arrangement, the structure is identical on each side of the centerline, only one side will be described in its preferred embodiment and it is duplicated on the opposite side of the centerline of the knife assembly. In order to attach the tang member of a blade to the driven connecting member 24, as shown in FIG. 3, each connecting member is provided with a resilient spring-like latch member 40 that preferably extends longitudinally of the driven member as shown. The latch member is thus disposed completely within the housing and no part extends out the opening 16. For connection with the blade tangs, the latch member is biased laterally inwardly, as by offsetting, as shown, and is attached cantilever-like at one end by fastening means 42 with the opposite free end 44 pressing inwardly of the housing or toward the center line 18. The particular arrangement described with the relatively long length of latch member 40 provides for good spring action and positive engagement as will be described. In order to connect the tang portion in a driving engagement with the latch, the latch member is provided with a cooperating engagement member such as aperture 46 of rounded, rectangular, or generally eliptical form and vertically disposed as shown. The engagement of aperture 46 of this type with the generally smaller cylindrical projection 38 has been found to achieve better tolerances of the engaging members, thereby producing a long life, positive drive, connection as pointed out in the aforementioned patent. Also placing the aperture 46 substantially at the free end provides the greatest moment for the positive driving connection with projection 38 on tang portion 32. While this is the preferred embodiment, it will be apparent that the lateral engagement of the projection-aperture can be reversed.

As described, it will be seen that when the tang portions of the knife blades are inserted in the opening 16 and forced rearwardly by the usual guiding elements formed directly on connecting members 24 as described in said patent, the spring action of respective latch members 40, by engagement with each of the connecting members, will positively and securely grip the respective projections 38 to lock the blades in place.

In order to release the engagement by the latching mechanism for removal of the blades, it is necessary to spread the adjacent latching members 40 and 48 as seen in FIG. 4. Further, in order to provide a smooth guiding and positive action in spreading the latch members it is desired to provide actuators as long as possible and well removed from any actuation or trigger mechanism which is normally directly back of opening 16 and on the bottom of the housing 10. To this end, a pair of supported and overlapping counter-reciprocating separate actuators 50 and 52 are provided as shown in FIG. 5. structurally, these may be relatively long because each actuator is adapted to contact the remote latch member by any suitable means. These actuators are provided .on opposite sides of the housing adjacent the opening and each actuator extends beyond the housing at one end to provide an external button. It is connected to the remote resilient latch member on the other end. Thus, actuator 50 is connected to the remote resilient latch member 40 by any suitable means such as extension 54 and similarly actuator 52 is connected by extension 56 to latch member 48. This provides the longest possible interconnection between the actuators and the latch members. The long connection feature is enhanced by providing the housing with suitable fiat guiding means 57 rearwardly of the opening 16 and the actuators 50 and 52 rest on the guiding means for pure straight line transverse operation. Housing may have one or more protube i g embe s 59 to p e s against the outer actuator 50 to help guide the actuators. This provides for long-life and smooth linear operation.

In order to provide a positive connection between the actuators in the latch structure, it has been found expedient to provide a reverse loop 58 on the free end of each latch member, the loop being conveniently formed by bending away from the center line or outwardly and away from the outwardly facing adjacent tang side to avoid any possible interference with the smooth operation of the latching structure. The provision of the reverse loop permits the extensions such as finger extension 54 to be inserted within the loop for a connection on spreading the latch member. Any suitable connection between the actuators and latch members may be used but the specific structure described provides an easily formed arrangement. Twisting of the extension 54 as shown fills the bight of the loop and avoids lost motion. Additionally, any suitable means may be provided to prevent any disengagement, as for example, making the loop 58 sutficiently lon or using a non-separable connection.

While the preferred embodiment of the latching structure has been shown, it will be apparent that the projection-aperture structure may be reversed and the detailed actuator structure may be varied considerably by providing an over-under connection across the tangs and various interconnections differing from extensions 54 and 56 may be used. The only requirement is that the actuators should connect on opposite sides of the centerline with the respective remote latching member for maximum guidance, smooth operation, and correct motion of the latch members which thus requires the overlapping actuator structure. Thus, within the scope of the attached claims, the structure may be varied as described.

I claim:

1. In an electrically operated slicing knife having a housing with a blade receiving opening at one end:

an electric motor within said housing adapted to be connected to a source of power;

a pair of driven members within said housing connected to said motor to be driven thereby with a counterreciprocating motion;

a pair of knife blades each having a forward cutting portion and a rearward tang portion;

each of said tang portions being adapted for insertion into said opening to be driven by said motor;

the improvement comprising,

a lateral engagement member on each tang portion oriented for engagement from its outwardly facing side;

a resilient latch member within said housing connected to each driven member and biased inwardly toward said outwardly facing tang side;

a cooperating engagement member on each latch member for driving engagement with the lateral engagement member when said tang is inserted in the opena pair of supported overlapping counter reciprocating separate actuators on opposite sides of said housing adjacent said blade opening;

each actuator extending beyond said housing at one end and connected to the remote resilient latch member on the other end;

whereby a pinching motion by the operator on said one end of each actuator spreads the latches separating said engagement to release said tangs from their respective driven members.

2. Apparatus as described in claim 1 Where the lateral engagement member comprises a projection on each tang portion directed outwardly and said cooperating engagement member is an aperture on each latch member.

3. Apparatus as described in claim 2 wherein each resilient latch member extends longitudinally and is connected at one end cantilever-like to said driven member, the'other free end being biased inwardly toward said out wardly facing tang side.

4. Apparatus as described in claim 3 wherein the free References Cited end of said latch has means connecting with its remote UNITED STATES PATENTS actuator operatim thereby 3 153 852 10/1964 Freeman 30 272 5. Apparatus as described in claim 4 wherein said latch 3234649 2/1966 Preble at H 30 272 connecting means includes a reverse 100p openin away 5 3:315:356 4/1967 Swanke et 5 3O 272 from said outwardly facing tang side and the remote actu- 3,322,925 5/1967 Korshak 30 272 X ator is provided with an extension disposed within said 37 95 3 19 7 Rosen 30-272 l op f r retenti n t ere n. 3,337,954 8/1967 Robison 30-272 6. Apparatus as described in claim 4 wherein said housing is formed with flat guiding means rearwardly of said 10 MY RON C. KRUSE, Primary Examineropening and said actuators rest thereon for straight line US. Cl. transverse operation. 30336 

